As a surgical treatment device, there is known a device in which, by utilizing microwaves, coagulation, hemostasis, incision, and the like are performed with respect to body parts such as the digestive organ, the liver, the bladder, the prostate gland, the uterus, the vessel, and the intestinal canal.
In a conventional electrosurgical knife or the like, the surface of the body tissue is heated and coagulated with the Joule heat generated using a high-frequency voltage having a main frequency of 500 kHz. In the coagulation with the Joule heat performed by the conventional electrosurgical knife or the like, the body tissue is rapidly coagulated, and hence the coagulated surface may be peeled off and dropped from the body tissue.
On the other hand, in the coagulation and the hemostasis utilizing the microwaves, the body tissue is grasped between electrodes, and the microwaves are applied to the body tissue. When the microwaves are applied to the body tissue, dielectric heat is generated, which is caused by the near electromagnetic field generated by the microwave electric power. The body tissue can be coagulated by evaporating moisture from the body tissue by the dielectric heat.
In the case of the coagulation and the hemostasis utilizing the microwaves, the body tissue can be mildly coagulated, and hence the body tissue can be kept in a fixed state where its function is stopped while maintaining the cell shape of the body tissue. In this manner, it is possible to prevent a situation that the coagulated surface is peeled off and dropped from the body tissue.
As a device which performs coagulation, hemostasis, incision, and the like of the body tissue by utilizing microwaves as described above, Patent Literature 1 discloses a medical treatment device in which a central electrode and an outer electrode are arranged in such a manner that leading end portions thereof are inclined in the same direction with respect to an axial direction of an outer conductor, and when the outer conductor and a moveable conductor are relatively shifted in the axial direction, the central electrode and the outer electrode are slidingly and relatively shifted along the inclined direction, to thereby cut the body tissue between the central electrode and the outer electrode. In addition, Patent Literature 2 discloses a medical treatment device which is designed so that both blades become parallel to each other at the time of grasping.